hisas driving 32 people from a connecticut casino to new york's chinatown when his bus hit a guardrail, toppled, and was torn open by a signpost. williams claimed he'd been cut off by a tractor-trailer. investigators found no evidence of that. but they discovered williams averaged three hours of sleep in the days before the crash. they cited driver fatigue as the probable cause. florence wong's father don lee was killed in the crash. >> he had 15 lives that was under under his control and they're not here. he has to live with that with conscinscience. >> reporter: prosecutors called 55 witnesses but could not produce direct evidence that lack of sleep impaired williams' driving. iredr goelz is former director of the national transportation arfety board. >> i think a guilty verdict would have sent a very strong eporage to these operators. disceporter: regulators shut dwn 26 discount bus companies for safety and driver violations last spring. >> it's a particular problem in the bus industry because oftentimes consumers have no way of checking whether that operator has got a good record o